Dishwashing machine



Oct. 30, 1962 B. c. A. LUNDSTEDT 3,060,947

DISHWASHING MACHINE Filed Aug. 29, 1961 3 Sheets-Sheet 1 Oct. 30, 1962 B. c. A. LUNDSTEDT 7 DISHWASHING MACHINE 3 Sheets-Sheet 3 Filed Aug. 29, 1961 11' FIG. 5

an M wm/ f7 United States Patent Ofifice 3,%0,947 Patented Get. 30, 1962 1 3,96%,947 DESHWASHENG MACHENE Bror Carl Axel Lundstedt, Vallinghy, Sweden, assignor to Aittieholaget Eiectrolux, Stockholm, Sweden, a cornoration of Sweden A Filed Aug. 29, 1961, Ser. No. 134,647

Claims priority, application Sweden Sept. 21, 1960 Claims. (Cl. 134-186) My invention relates to dishwashing machines.

Dishwashing machines have been provided in which dishes and other articles to be washed are placed in a casing and water is sprayed against them by a pump whose inlet is located in a relatively small sump which is disposed at the underside of the casing and provided with an outlet in its lower part adapted to be closed by a control valve. When Water fiows continuously through a dishwashing machine of this type during the cleaning of the dishes, as when they are being initially rinsed or flushed before being washed with a detergent, for example, 1t is desirable to operate the dishwashing machine a minimum quantity of water, and, for this reason, the inlet of the pump is located in the relatively small sump rather than in a part of the dishwashing machine of wider diameter. However, difiiculty is sometimes encountered in keeping water supplied continuously to the inlet of the pump, and this is especially true when the pressure of the available water supply is low.

It is an object of my invention to provide an improvement in dishwashing machines of this type whereby the liquid level in the sump can be effectively controlled and regulated during operation of the machine under all operating conditions encountered. I accomplish this by providing a partition or dam in the sump between the inlet of the pump and the outlet. The partition is movable and cooperates with the control valve for the outlet in such a manner that the control valve can function normaily to close and open the sump outlet and the partition can function under certain operating conditions to maintain a body of water in the sump when the control valve for the outlet is open.

The above and other objects and advantages of my invention will become apparent as the following description proceeds, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention, reference may be had to the following description taken in connection with the accompanying drawing, in which:

FIG. 1 is a side perspective view of a dishwashing machine embodying my invention, the cover being open to illustrate the interior of the machine;

FIG. 2 is a bottom perspective view of the dishwashing machine shown in FIG. 1;

FIG. 3 is a horizontal sectional View of the dishwashing machine shown in FIG. 1 with the dish supporting structure removed;

FIG. 4 is a fragmentary vertical sectional view of the dishwashing machine shown in FIGS. 1, 2 and 3; and

FIGS. 5, 6 and 7 are fragmentary horizontal views, partly in section, of parts illustrated in FIG. 4, the several views showing the same parts in different operating positions.

Referring to the drawing, the dishwashing machine embodying my invention comprises a cylindrical casing 10 having a base 11 and an upper part 12 defining a space 9. As best seen in FIG. 4, the base 11 includes a bottom 14 and a short upstanding side wall 15 which is connected at 16 to the bottom edge of the upper part 12. The upper part 12 is of inverted cup shape having an upstanding side wall 17 and a flat top 18.

As best shown in FIG. 2, the bottom of the base 11 is provided with spaced feet or supports 19 positioned within an annular skirt or flange 20 to shield parts at the bottom of the dishwashing machine. The upper part 12 is formed with a wide angle opening 21 formed in the upstanding side wall :17 and flat top 18. A soft resilient gasket 22 is provided at the spaced vertical edges 23 of the opening 21, as shown in FIGS. 1 and 3.

A door 24 having the same configuration as the side wall 17 and top 18 and provided with a handle 25 is mounted for sliding movement in any suitable manner within the upstanding side wall 15 of the bottom 11. The door 24 is movable between its open and closed positions illustrated in FIGS. 1 and 3, the dish rack 26 within casing 10 being accessible when the door is open. The dish rack 26 is mounted on a rotatable member 27 which is arranged to be driven through reduction gearing, indicated generally at 28 in FIG. 3, by a vertical shaft 29 extending upward through a hollow tube 30 within the casing 10. The shaft 29 at its upper end is connected to an enclosed electric motor 31 which is fined to the underside of the top 18 and controlled by a manually operable control member 3'1a located at the top of the casing and accessible when the door 24 is closed.

Liquid is supplied to the dishwashing machine in a liquid supply line which includes a flexible hollow tube 32 having a resilient coupling 33 at its outer free end adapted to be connected to a faucet or water tap. Liquid is conducted through tube 32 to a vacuum breaker 34 comprising a receptacle 35 having a top opening 35 beneath which is disposed an air vent tube 37 fixed to a horizontal plate 38. A drain opening 39 is provided at the bottom of receptacle 35 for draining liquid into a trough 40 from which liquid can pass through an opening 41 into the interior of the casing 10. Liquid is delivered tangentially into the receptacle 35 to impart a swirling movement to the liquid which passes from the receptacle through a conduit 42 connected to its side wall. The liquid passing through the receptacle 35 will be at atmospheric pressure and is discharged tangentially therefrom into conduit 42 which extends downward along the side of casing 10 and radially inward at the bottom of the casing, as best seen in FIG. 2.

The lower end of conduit 42 is connected at 43 to the sidewall of a relatively shallow pan 44 which forms a sump 45 at the extreme bottom of the dishwashing machine. The pan 44 is formed with an outwardly extending flange 44a which is secured at 46 to the bottom 14 of base 11 about an opening 14a therein.

The electric motor 31 drives the rotatable member 27 upon which the disk rack 26 is mounted, as explained above, and also a pump 47 which is connected to the lower end of vertical shaft 29. As best shown in FIG. 4, the inlet 48 of pump 47 is directed downward toward the bottom 45a of the sump 45 and is at a level below the region 43 at which liquid is delivered to the sump through the conduit 42. Liquid discharged from the pump 47 is delivered through a number of apert-ured tubes 49 which are spaced from one another and distributed within the space 9 for spraying dishes to be washed with liquid while they are being rotated past the tubes. Liquid collects in the bottom of the casing 10 and flows along the bottom 14 toward the sump 45, the bottom sloping downward toward the central opening 14a therein.

As seen in FIGS. 2 and 5, a short pipe section 50 having an opening in its wall is fixed at 51 to the side wall 45b of the sump 45 with the pipe opening being in alignment with an opening in the side wall of the sump 45 and defining an outlet 52 for liquid discharged from the dishwashing machine. As shown in FIG. 4, the outlet extends through a vertical height in the sump 45 from spouse? the vicinity of the bottom 45a to the vicinity of the flange 440. One end of pipe section 50 is connected to an L- shaped fitting 53 having an arm 54 which extends upward through an opening in the bottom '14 of base 11. The arm 54 serves as an overflow pipe which extends upward within the deeper center part 14b of the base 11 and has its inlet at a level slightly below the outer fiat rim portion 14s of the bottom of the base 11. The liquid discharged from the outlet 52 and liquid passing through the overflow pipe 54 flows into the pipe section 50 to which is connected a hollow flexible tube 55 for conducting liquid to waste.

LA valve 56 for controlling flow of liquid through the outlet 52 is fixed to a rod 57 which extends through an opening in the wall of pipe section t] and an opening formed in an arm 58 of a bracket 59 fixed to the pipe section. An L-shapcd lever 60 is pivoted at 61 to the bracket 59, one arm of which is provided with a manually operable control knob 62 and the other arm of which is provided with a pin 63 movable in an elongated slot 64 formed in an apertured part 65 of the rod 57.

In order to prevent foreign matter from being drawn into the inlet 48 of pump 47 from the sump 45 an apertured plate 66 is provided in the sump which slopes downward toward the bottom edge of the outlet 52 from a diametrically opposite region of the sump 45 at a level at the vicinity of the flange 44a, as shown in FIG. 4. The apertured plate 66, which is formed with a central opening and is of annular form and encircles an upstanding wall 47a about the pump, in effect serves as a strainer and acts to direct toward the outlet 52 foreign matter collecting in the sump 45.

In accordance with my invention, in order to control and regulate the liquid level in the sump 45 during operation of the dishwashing machine, I provide a partition 67 in the sump between the inlet 48 of the pump 47 and the outlet 52. The partition 67, which is fixed at 68 to the inner end of rod 57, is spaced from valve 56. The partition '67 desirably is flexible and formed from relatively thin material which is highly resistant to corrosion, such as Phosphor-bronze, for example. As illustrated in FIG. 7, the partition 67 in its unflexed state in cludes a vertical center strip 67a parallel to valve 56 and side strips 67b which are inclined at an acute angle toward the outlet 52 from the vertical plane of the center strip.

The bottom edge of the partition 67 is in intimate physical contact with the bottom 45a of the sump 45 and remains in good contact therewith when it is moved toward and from the outlet 52. Desirably, the partition 67 should extend upward a vertical height which at least approaches the height of the sump 45. As illustrated in FIG. 4, the partition 67 extends upward to a region which is slightly above the position of the flange 44a.

When the valve 56 is moved to its closed position by the knob 62 and the outlet 52 is closed, as shown in FIG. 5, the partition 67 is flexed with the side strips 67b parallel to the center strip 67a and the lateral vertical edges of the partition in good physical contact with the side wall 45!) of the sump 45.

In FIG. 6 the knob 62 is in such a position that the valve 56 is in an open position while the lateral vertical edges of the partition 67 are still in good physical contact with the side wall 45b of the sump 45. In FIG. 6 the partition 67 desirably is in a partly flexed state to insure that a liquid-tight seal is eflected at both the bottom and side vertical edges of the partition.

In FIG. 7 the knob 62 is in such a position that valve 56 is in an open position and the partition 67 is out of contact with the side wall 45b of the sump 45, so that liquid can freely flow from the sump 45 through the outlet 52. a

The dishwashing machine illustrated and just described can be operated by initially rinsing dishes and other articles to be washed. After placing the dishes on the dish rack 26 and closing the door 24 and moving the 4 control knob 62 to the position illustrated in FIG. 6 to move valve 56 to its open position and render partition 67 effective to control and regulate the liquid level in the sump 45, the coupling 33 of the tube 32 is connected to a source of water, either hot or cold, and the switch 31a is operated to start the electric motor 31.

The motor 31 now is rendered operable to drive the rotatable support 27 upon which the dish rack 26 is mounted and the pump 47 will be rendered operable to withdraw water from the sump 45 and such water will be discharged from the pump and sprayed from the apertured pipes 49 against the dishes. The water discharged into the space 9 will flow by gravity toward the bottom 14 and collect in the sump 45.

It is desirable to initially rinse and flush dishes to be washed by continuously flowing water through the dishwashing machine rather than by recirculating water through the machine. By providing the partition 67 to keep the sump 45 more or less filled with liquid, liquid can flow continuously through the machine from the supply conduit 42 to the outlet 52 after the sump becomes tilled with liquid and flows over the top edge of the partition 67. The overall quantity of liquid required for initially rinsing dishes is materially reduced by providing the partition 67 because the entire quantity of liquid required by the pump 47 for its operation is held in the sump 45 whose diameter is substantially smaller than the diameter of the main space 9 of the dishwashing machine in which the dishes are supported.

By employing a relatively small sump 45 in which the inlet 48 of the pump 47 is located and providing the partition 67 to insure that the sump will be filled with liquid even when pre-rinsing and flushing is being effected by continuously flowing Water through the machine, the quantity of water required per unit of time for such continuous flow operation is relatively small and initial rinsing and flushing of dishes can be successfully accomplished even when the pressure of the available water supply is low.

After the dishes to be washed have been initially rinsed or flushed for about a minute or so, the dishes may then be Washed by moving the control knob 62 to the position illustrated in FIG. 5 tomove valve 56 to its closed position and by connecting the coupling 33 to a source of supply of hot water and operating switch 31a to start the electric motor 31. After hot water starts overflowing through overflow pipe 54, which will be observed when water commences to flow to waste through conduit 55, the hot water supply can be shut ofi. Under these conditions the quantity of water supplied to the dishwashing machine is comparatively =large because the liquid rises in the bottom of space 9 to the level of the overflow pipe 54. The body of water is held in space 9 at the deep center part 14b of the base 14 whose diameter is considerably greater than that of the sump 45. The door 24 now is opened momentarily to add a quantity of detergent upon the dishes. With the door 24 closed and the motor 311 still rendered operable to drive the rotatable dish rack 26 and to operate the pump 47, hot water will be recirculated in the machine for spraying water on the dishes. After four or five minutes, for example, the control knob 62 is moved to the position shown in FIG. 7 to move valve 56 to its open position, so that all of the water will drain from the ma chine. With all of the washing liquid drained from the machine and the valve 56 and partition 67 still in the positions illustrated in FIG. 7, Water is again supplied to the machine, the motor 31 still being effective to rotate the dish rack 26 and operate the pump to rinse the dishes for about 1 /2 minutes. Under these conditions water flows continuously through the dishwashing machine.

Although I have shown and described a particular embodiment of my invention, I do not desire to be limited to the particular arrangement set forth, and I intend in the following claims to cover all modifications which do not depart from the spirit and scope of the invention.

I claim:

1. In a dishwashing machine of the class described, the combination of a casing defining a space, means for supporting dishes and other articles to be washed in the space, means including a pump for directing liquid toward the dishes, said casing below the space in which the dishes are supported having a sump provided with an outlet for liquid in the bottom part thereof, control means including a valve movable from and to a closed position for controlling flow of liquid by gravity from said sump through the outlet, means for moving said valve from and to its closed position, said pump having an inlet in said sump, means connected to the machine for supplying liquid to said sump from a source of supply, and means for regulating the liquid level in said sump when liquid is being continuously circulated through the machine with liquid being supplied to said sump through said liquid supply means and liquid flowing by gravity from said sump with said outlet valve away from its closed position, said regulating means including a member disposed between the inlet of said pump and the outlet to maintain the liquid level in said sump above the inlet of said pump when the latter is operative and liquid is being continuously circulated through the machine.

2. The dishwashing machine set forth in claim 1 in which said regulating means includes provisions for moving said member between two positions in one of which it is operable to regulate the liquid level in said sump and in the other of which it is inoperable to regulate the liquid level in said sump.

3. The dishwashing machine set forth in claim 2 in which said means for moving said valve includes an element, said provisions for moving said member including said element.

4. The dishwashing machine set forth in claim 3 in which said element comprises an elongated rod to which said valve is fixed, said member being fixed to said rod between the outlet and the inlet of said pump.

5. The dishwashing machine set forth in claim 4 in which said member comprises a sheet of flexible material.

6. The dishwashing machine set forth in claim 5 in which said sheet is vertically disposed and carried by said regulating means and movable in said sump with its bottom edge in good physical contact with the bottom of said sump while its lateral side edges are movable into and out of physical contact with the side wall of said sump at opposite sides of the outlet, the top edge of said sheet being out of contact with other parts in said sump and space.

7. The dishwashing machine set forth in claim .6 in which the top edge of said sheet is at a level which approaches the top of said sump.

8. The dishwashing machine as set forth in claim 6 in which the top edge of said sheet is at a level slightly above the top of said sump.

9. The dishwashing machine as set forth in claim 5 in which said member and said valve are positioned on said rod and movable to three positions in one of which said valve closes the outlet and said sheet functions as a partition between the inlet of said pump and the outlet, in a second of which said valve is ineflective to close the outlet and said sheet still functions as a partition between the inlet of said pump and the outlet, and in a third of which said valve is ineffective to close the outlet and said sheet is ineffective to function as a partition between the inlet of said pump and the outlet.

10. The dishwashing machine set forth in claim 5 in which a drain conduit communicates with the outlet and receives liquid flowing by gravity from said sump, an overflow pipe which is arranged to receive liquid from the bottom of said space and is connected to said drain conduit, said sheet functioning as a partition in said sump over the top edge of which liquid is adapted to flow, said overflow pipe being located in that part of the space having a cross-sectional area greater than that of said sump, and said overflow pipe being arranged to receive liquid from said space at a higher level than the top edge of said partition.

References Cited in the file of this patent UNITED STATES PATENTS 1,157,643 Kuhn Oct. 19, 1915 1,511,825 Burns Oct. 14, 1924 1,884,180 Pauly Oct. 25, 1932 2,071,036 Johnston Feb. 16-, 1937 2,608,993 Andrews Sept. 2, "1952 2,652,854 Stoddard Sept. 22, 1953 FOREIGN PATENTS 47,689 Norway Mar. 24, 19-30 

